If you accept that the basic theme of Animal kingdom revolves around man and the natural world then zootopia would not fit.
Not only that, but the biggest difference between Animal Kingdom and every other park at Disney World, or Florida in general, is that it the aesthetic of the park maintains a near-perfect tone of realistic hyper-reality. As opposed to say, the Magic Kingdom, where you have a Georgia mountain full of antebellum singing half-animal creatures next door to a late-1800s western mining railway in the same "land," every ride, restaurant, and shop in the Animal Kingdom is in perfect harmony with the themed reality of its area and requires minimal suspension of disbelief. To that end, every attraction vehicle also exists as it should be- the vehicles for the safari are safari trucks and the raft expedition company at Kali sure enough puts you on a raft. Again, as opposed to the Magic Kingom, where there's a massive unbroken chain of bubble-shaped benches moving through the Haunted Mansion because....? In this way, every area in the Animal Kingdom off of the hub is one that does, or
could exist in our world. Pandora is far from a perfect fit, but at least it's a live-action science fiction universe with its own non-magical logic and not, say, Treasure Planet, or even Star Wars.
The only possible exceptions are Theater in the Wild, which is either totally unthemed and/or part of Dinoland, and It's Tough to be a Bug, which is nestled so far inside a maze of walkways that it doesn't "taint" the area around it with its cartoony-ness. Same deal for Rafiki's Planet Watch, which is so far removed from the "real" part of Africa that you can't even get there on foot.
I'm not saying one approach is better than the other, but the fact that Animal Kingdom had such a successful run of adhering to its own themed realities that it would be a shame to break it now.
So as we've discussed, Zootopia is an obvious fit because, uh, animals? but an absolutely terrible fit for every other possible reason.
There is only one word to describe the appropriate future for Disney's Animal Kingdom: